"The publisher gets to define that, actually. What will happen is, the PS4 digital file will be made available on the PlayStation Store - as it would be anyway - at launch, and the PS3 discs will be sold through retail," Sony UK managing director Fergal Gara told Digital Spy at gamescom 2013.

"What the consumer can then do, for a premium to be defined by the publisher, is access the PS4 digital game and then provided they still have the PS3 disc, they will be able to play the PS4 version when they decide to buy the next gen.

"Time window and price window has yet to be defined. Time window is probably more business policy for PlayStation, perhaps, but the premium will be defined by the publisher."

The limited-time offer was announced at gamescom this week. Ubisoft, EA, Activision and Warner Bros are among the publishers announced to be taking part in the scheme.

"We've offered people the upgrade path for a modest fee. I think it's another very much gamer-focused policy piece of tech we've been able to bring to market, and it enables publishers to bring their current gen gamers onto the next gen," Gara added.

The PlayStation 4 will launch in North America on November 15 and in Europe on November 29, retailing at $399/€399.